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A spat between innovative or, depending on who you ask, careless orthopedic surgeons on each side of the Atlantic Ocean has spilled over into the public domain in spectacular fashion, and now into the courts in the form of a good, ol' fashion product liability class action suit.

In the balance: a crippled minority all having learned, the hard way, how to spell o-s-t-e-o-a-r-t-h-r-i-t-i-s.

Hip Replacement Surgery Described

Hundreds of thousands of patients of all ages require hip replacement surgery every year for a variety of reasons, the most frequent cause being osteoarthritis.

"The hip is one of the body's largest joints. It is a ball-and-socket joint. The socket is formed by the acetabulum, which is part of the large pelvis bone. The ball is the femoral head, which is the upper end of the femur (thighbone). The bone surfaces of the ball and socket are covered with articular cartilage, a smooth tissue that cushions the ends of the bones and enables them to move easily. A thin tissue called synovial membrane surrounds the hip joint. In a healthy hip, this membrane makes a small amount of fluid that lubricates the cartilage and eliminates almost all friction during hip movement.

"The most common cause of chronic hip pain and disability is ... osteoarthritis … an age-related wear and tear type of arthritis. It usually occurs in people 50 years of age and older and often in individuals with a family history of arthritis. The cartilage cushioning the bones of the hip wears away. The bones then rub against each other, causing hip pain and stiffness. Osteoarthritis may also be caused or accelerated by subtle irregularities in how the hip developed in childhood….

"In a total hip replacement (also called total hip arthroplasty), the damaged bone and cartilage is removed and replaced with prosthetic components."

The so-called total hip replacement procedure involves cutting through skin and muscle, dislocating the hip, reaming the acetabulum and placing a durable polyethylene membrane inside. The femoral head is then sawed right off and a long stake driven into the femur stump on which is fixed a ball which is then reinserted into the new artificial and flexible polyethylene membrane in the reamed hip socket. For those not faint of heart, an animated film of the procedure is available on YouTube.

The Birmingham Hip

In 1997, orthopedic surgeon and inventor Dr. Derek McMinn of Birmingham, England contrived and first used a simplified procedure now known as hip resurfacing. The hip joint was dislocated, the socket reamed and a metal bowl inserted. The femoral head was not cut off. Instead, it was merely resurfaced with a metal cup. Then, metal-on-metal, the resurfaced femoral head was snapped back into the metal-lined acetabulum. The theory was that the body's natural fluids then acts as a membrane between the two metal pieces causing them to hydroplane and never actually coming into contact. Again, animation available on YouTube.

It appears to be ingenious: the femoral head is retained and the operation avoids all the precise calibration of parts and angles in the total hip replacement process.

Because the recovery time is quicker and the operation less traumatic particularly on the femur, medical tourists began to visit Birmingham for the resurfacing procedure. Birmingham, in turn, began to train orthopedic surgeons in other countries to offer the hip resurfacing procedure. Dr. McMinn's website, at mcminncentre.co.uk, remains an unrepentant champion of the procedure.

Hip resurfacing has spawned a significant medical tourism industry where, for example, a trip to Mexico or India will not only provide the operation with little delay, but at a fraction of the cost.

Indian websites abound all rife with eyebrow-raising marketing jingles:

"Hip resurfacing is considered better than total hip replacement because generally after the latter is done, one cannot sit on the floor, squat, or lead a very active, hectic life or play sport", Medical Tourism Corporation; and

"Hip Resurfacing is a new revolution in the treatment of Arthritis of Hip Joint. It is a much superior alternative to hip replacement", Hip Resurfacing Centre.

The Birmingham hip procedure was met with open arms by patients who were enthusiastic about the much shorter recovery period, but with some suspicion by other orthopedic surgeons especially in regards to the metal-on-metal feature. Metal-on-metal implants, the theory initially went, was easier on the remaining hip joint. A comment in a 2009 article in Issues in Law & Medicine was typical:

Resurfacing Second-Fiddle to Replacement

The traditional "total hip replacement" procedure is older but still a relatively new technology, only first done in 1960, according to the American Academy of Orthopedic Surgeons, but since greatly improved. The polyethylene material used for the all-important membrane, and the choice of metal being amongst the more important enhancements. An aging population has also provided never-ending supply of patients to continuously improve the surgical techniques and devices: more than 285,000 total hip replacements are performed each year in the United States alone.

This is big business, so big that hip surgery options and clinics now plaster billboards in large American cities and are even the subject of television commercials.

The Birmingham hip resurfacing option has not been universally received by the orthopedic community to the extent of traditional hip replacement surgery, which is now practically available in every major city in North America. While millions of Americans have had traditional hip replacement surgery since 2003, only 500,000 have opted for the metal-on-metal hip joint procedure, a situation exacerbated by delays inherent in American regulatory approval of the device (FDA). In Canada, only a handful of surgeons offer the procedure.

Complaints to health authorities from patients about metal-on-metal hip devices have skyrocketed reaching 12,000 in 2011 alone. The shelf life of a traditional hip replacement is almost 20 years. According to an article published in the New England Journal of Medicine in July 2012 by Dr. Joshua Rising:

"There is now compelling evidence that (metal-on-metal) implants fail at a higher rate than hip prostheses made of other materials; indeed, one type of metal-on-metal hip has a failure rate of nearly 50 percent at six years."

Failure rate is not the only problem. The metal-on-metal option, hydroplaning notwithstanding, inevitably causes the release of metal into the body, accelerating as the joint becomes worn down. Blood tests on patients show high levels of potentially toxic metal ions, cobalt and chrome, the metals used in the alloy the device is made of.

This has not been lost on lawyers who have picked up the baton in regards to the shortcomings of the metal-on-metal option. Several class-action suits are now proceeding to the courts and some of the hip resurfacing components have actually been recalled:

"Metal-on-metal devices have already been recalled twice. In 2008, a device from manufacturer Zimmer, the Durom Acetabular Component, was recalled …. In 2010 a device from DePuy Orthopaedics Inc. was recalled…. (In June 2012) the R3 Acetabular System from Smith & Nephew was taken off the market…."1

"The National Joint Registry of England and Wales reported in 2010 that the overall revision rate for primary hip replacements is 2.1% at 3 years and 2.9% at 5 years. The British Orthopaedic Association has identified; however, that failure rates for the DePuy ASR range from 21% at 4 years to 49% at 6 years."

At the end of June a small group of experts met in Washington, DC, to consider some of the shocking reports then coming from the surgical and academic research fronts. One government document:

"Evidence mounting that the devices deteriorate sooner than other implants, shedding particles of metal into the surrounding joint and bloodstream…. Tiny fragments of metal can shear off from these artificial joints, causing chronic pain or infection and raising levels of metals in the bloodstream.

"Of the estimated 400,000 hip replacements done in the United States each year, 27 percent involve metal-on-metal devices."1

Some surgeons in Britain signed-off on an article published in the national medical journal The Lanclet that called for an outright ban:

"Metal-on-metal stemmed articulations give poor implant survival compared with other options and should not be implanted."

This professional reluctance has had predictable effect with statistics collected by the National Joint Registry in London showing that hip resurfacing in England declined from a peak of 6,500 procedures in 2006, to on 2,500 (in 2010).2

An Imperfect Status Quo

Not all hip implants are metal-on-metal; in fact, most are not. Even some resurfacing surgeries use plastic and ceramic parts.

Not all manufacturers are created equal. There are over seventy different models of artificial joints available to surgeons.

No surgical solution that involves replacing a natural joint with a prostheses is perfect.

"With a plastic socket, you get tiny fragments of plastic collecting around the hip joint in a kind of sludge. But with metal, although it is harder and will theoretically last longer, there is the risk of tiny metal particles entering the bloodstream."3

The truth, as truth outs when the wheels of justice turn, will also be imperfect. But as patients with painful hips inch towards one of the most important decisions of their lives - to resurface or not to resurface - the product liability drama will play out slowly to a verdict in Courtrooms of England and America, just like a John Grisham novel. The court will certainly hear from a core group of surgeons who have not given up on metal-on-metal hip resurfacing as a good alternative under some conditions.

Unfortunately, for the thousands caught in this time of surgeon wariness and consumer confusion, the ravages and constant painful pangs of osteoarthritis neither abides nor waits.

For those that can't sit down, bend over or even walk without constant pain, metal-on-metal can hardly be worse than bone-on-bone.

Unless otherwise noted, this article was written by Lloyd Duhaime, Barrister, Solicitor, Attorney and Lawyer (and Notary Public!). It is not intended to be legal advice and you would be foolhardy to rely on it in respect to any specific situation you or an acquaintance may be facing. In addition, the law changes rapidly and sometimes with little notice so from time to time, an article may not be up to date. Therefore, this is merely legal information designed to educate the reader. If you have a real situation, this information will serve as a good springboard to get legal advice from a lawyer.